SiR-azide is the 3-azidopropyl derivative of the fluorophore silicon rhodamine (SiR). Sir-azide reacts with terminal alkyne derivatives in the presence of copper (I) to form 1,2,3-triazoles linkage. It can also react with strained alkynes such as DIFO or DIBO without the need of copper. Small molecules, peptides, oligonucleotides or proteins bearing the appropriate alkyne can be conjugated to SiR-azide. SiR-azide is compatible with GFP and/or m-cherry fluorescent proteins. It can be imaged with a standard Cy5 filterset.
